How to Fertilize hydrangea 'Ō-amacha'?
Hydrangea feed in spring and again early summer

hydrangea 'Ō-amacha' · Hydrangea serrata 'Ō-amacha'
Grow in moist but well-drained soil in partial shade or in full sun if soil remains reliably moist
Hydrangea feed in spring and again early summer